Outflowing Gas in Ultraluminous Galaxies

Galaxies evolve over billions of years in part through the activity of star formation and their supermassive nuclear black holes, and also by mergers with other galaxies.

Some features of galaxies, in particular the strong correlations found between the mass of the central black hole and properties like galaxy velocity structure or luminosity, imply a fundamental connection between the growth of the nuclear black hole and the assembly of stars on a global scale. Feedback of some kind is therefore expected to explain these tight correlations, and astronomers have been working to identify and study it. One prominent suggestion for feedback is the presence of warm outflowing gas, powered by new stars but which would deplete the galaxy of the raw material needed for making new stars, and/or for enhancing the black hole mass.

In the 1990s, the Infrared Space Observatory (ISO) detected evidence for warm gas in luminous galaxies, the molecule OH, and the recent Herschel Space Observatory followed up those detections with velocity-resolved observations of six of the prominent OH far infrared lines. CfA astronomers Eduardo Gonzalez-Alfonso, Matt Ashby, and Howard Smith led a team of scientists reducing and modeling the four strong lines in fourteen ultra-luminous infrared galaxies (ULIRGs). The set of OH lines from ULIRGs is remarkable in that they appear sometimes in absorption, sometimes in emission, and sometimes with a bit of both depending on the particular line and velocity component. Many of these spectral features are characteristic of gas moving in an outflow, and the team has developed a radiative transfer model to deduce the geometry and kinematics of the flowing gas from the complex line shapes.

The scientists report that there are indeed powerful outflows in these ULIRGs, some with more than a thousand solar-masses per year and the power of a hundred billion Suns (a few percent of the total luminous energy of the galaxy). The typical time it would take for this gas to be blown out of the galaxy is only a few hundred million years, and the astronomers conclude that the outflows must occur erratically (not continuously), and are probably tied to the equally random flaring activity of the central black hole, which in turn can be linked to the gas motions induced by galaxy mergers.

The Milky Way’s Black Hole is Spewing Planet-size Orbs

Every few thousand years, an unlucky star wanders too close to the black hole at the center of the Milky Way.

The black hole’s powerful gravity rips the star apart, sending a long streamer of gas whipping outward. That would seem to be the end of the story, but it’s not. New research shows that not only can the gas gather itself into planet-size objects, but those objects then are flung throughout the galaxy in a game of cosmic “spitball.”

“A single shredded star can form hundreds of these planet-mass objects. We wondered: Where do they end up? How close do they come to us? We developed a computer code to answer those questions,” says lead author Eden Girma, an undergraduate student at Harvard University and a member of the Banneker/Aztlan Institute.

Girma is presenting her findings at a Wednesday poster session and Friday press conference at a meeting of the American Astronomical Society.

Girma’s calculations show that the closest of these planet-mass objects might be within a few hundred light-years of Earth. It would have a weight somewhere between Neptune and several Jupiters. It would also glow from the heat of its formation, although not brightly enough to have been detected by previous surveys. Future instruments like the Large Synoptic Survey Telescope and James Webb Space Telescope might spot these far-flung oddities.

She also finds that the vast majority of the planet-mass objects – 95 percent – will leave the galaxy entirely due to their speeds of about 20 million miles per hour (10,000 km/s). Since most other galaxies also have giant black holes at their cores, it’s likely that the same process is at work in them.

“Other galaxies like Andromeda are shooting these ‘spitballs’ at us all the time,” says co-author James Guillochon of the Harvard-Smithsonian Center for Astrophysics (CfA).

Although they might be planet-size, these objects would be very different from a typical planet. They are literally made of star-stuff, and since different ones would develop from different pieces of the former star, their compositions could vary.

They also form much more rapidly than a normal planet. It takes only a day for the black hole to shred the star (in a process known as tidal disruption), and only about a year for the resulting fragments to pull themselves back together. This is in contrast to the millions of years required to create a planet like Jupiter from scratch.

Once launched, it would take about a million years for one of these objects to reach Earth’s neighborhood. The challenge will be to tell it apart from free-floating planets that are created during the more mundane process of star and planet formation.

“Only about one out of a thousand free-floating planets will be one of these second-generation oddballs,” adds Girma.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Scientists Close-in On the True Mass of Milky Way

It’s a problem of galactic complexity, but researchers are getting closer to accurately measuring the mass of the Milky Way Galaxy.

In the latest of a series of papers that could have broader implications for the field of astronomy, McMaster astrophysicist Gwendolyn Eadie, working with her PhD supervisor William Harris and with a Queen’s University statistician, Aaron Springford, has refined Eadie and Harris’s own method for measuring the mass of the galaxy that is home to our solar system.

The short answer, using the refined method, is between 4.0 X 1011 and 5.8 X 1011 solar masses. In simpler terms, that’s about the mass of our Sun, multiplied by 400 to 580 billion. The Sun, for the record, has a mass of two nonillion (that’s 2 followed by 30 zeroes) kilograms, or 330,000 times the mass of Earth. This Galactic mass estimate includes matter out to 125 kiloparsecs from the center of the Galaxy (125 kiloparsecs is almost 4 X 1018 kilometers). When the mass estimate is extended out to 300kpc, the mass is approximately 9 X 1011 solar masses.

Measuring the mass of our home galaxy, or any galaxy, is particularly difficult. A galaxy includes not just stars, planets, moons, gases, dust and other objects and material, but also a big helping of dark matter, a mysterious and invisible form of matter that is not yet fully understood and has not been directly detected in the lab.
Astronomers and cosmologists, however, can infer the presence of dark matter through its gravitational influence on visible objects.

Eadie, a PhD candidate in Physics and Astronomy at McMaster University, has been studying the mass of the Milky Way and its dark-matter component since she started graduate school. She uses the velocities and positions of globular star clusters that orbit the Milky Way. The orbits of globular clusters are determined by the galaxy’s gravity, which is dictated by its massive dark matter component.

Previously, Eadie had developed a technique for using Globular Cluster (GCs) velocities, even when the data was incomplete.

The total velocity of a GC must be measured in two directions: one along our line-of-sight, and one across the plane of the sky, called the proper motion. Researchers have not yet measured the proper motions of all the GCs around the Milky Way. Eadie, however, had previously developed a way to use these velocities that are only partially known, in addition to the velocities that are fully known, to estimate the mass of the galaxy.

Now, Eadie has used a statistical method called a hierarchical Bayesian analysis that includes not only complete and incomplete data, but also incorporates measurement uncertainties in an extremely complex but more complete statistical formula. To make the newest calculation, the authors took into account that data are merely measurements of the positions and velocities of the globular clusters and not necessarily the true values. They now treat the true positions and velocities as parameters in the model (which meant adding 572 new parameters to the existing method).

Bayesian statistical methods are not new, but their application to astronomy is still in its early stages, and Eadie believes their capacity to accommodate uncertainty while still producing meaningful results opens many new opportunities in the field.

“As the era of Big Data approaches, I think it is important that we think carefully about the statistical methods we use in data analysis, especially in astronomy, where the data may be incomplete and have varying degrees of uncertainty,” she says.

Bayesian hierarchies have been useful in other fields but are just starting to be applied in astronomy, Eadie explained.

Exploded Planet Hypothesis Source of Earth’s Moon

First, I am compelled to set the record straight as to who was the first to publish their scientific papers as to the source of how Earth’s moon came to be. It was Dr. Tom Van Flandern who past away on the very same date (January 9th) this article was published yet 8 years prior. (see orbit)

I mention this because he was ridiculed, essentially blackballed, from the astronomical community simply because he stood firm to his convictions. No, not based on some hunch, but hard scientific research filled with countless hours of checking and re-checking his data. The only mention he received in this article was the following:

Raluca Rufu, a researcher at the Weizmann Institute of Science in Israel and lead author of the study are not the first to propose a multiple-impact scenario. Another paper published in 1989 raised that possibility, but “no further work was done on the subject,” Rufu said. “This paper is first to provide extensive calculations that we hope will stimulate others to reexamine the issue.”

In 1989, Dr. Van Flandern published is paper titled “Exploded Planet Hypothesis” identifying the early nature of our solar system. I would call that more than just “another paper published in 1989”. Does this latest article seem to strike a note of a personal nature? Yes it does. It is known Tom was more than just a scientist I had on my show several times, we became friends – he was more of a mentor, perhaps knowing of what I would go through as I was presenting new data supporting my Sun-Earth-Extreme Weather hypothesis.

Dr. Van Flandern’s pedigree far exceeds my own, yet when he could no longer tow-the-line of his colleagues simply because he could not deny the outcome of his research. It was sometime after 1989 he became the target from the very agencies he worked with. From 1963 to 1983, Tom was the top shelf astronomer at the U.S. Naval Observatory becoming Chief of the Research Branch and later becoming Chief of the Celestial Mechanics Branch of the Nautical Almanac Office.

Tom Van Flandern held memberships in the International Astronomical Union, the American Astronomical Society (and in its Divisions on Dynamical Astronomy and Planetary Sciences), and several other scientific organizations. He received second prize from the Gravity Research Foundation in 1974 and the Astronomy Award from the Washington Academy of Sciences in 2000.

And now, in an article published on Jan. 9th 2017, he is addressed as “just some another paper published in 1989 blah blah blah”. They appear to have taken his research mostly known as “Exploded Planet Hypothesis” and renamed it “Multiple Impact Hypothesis”. Yes, this really happened.
See the article below….

Earth’s Moon Formed in ‘Moonlet’
Mash-Up After Many Earth Impacts

Earth’s moon may be the product of many small moonlets that merged after multiple objects as big as Mars collided with Earth, leaving disks of planetary debris orbiting the planet, a new study suggests.

This idea that multiple impacts led to the moon’s birth challenges the most prevalent theory of lunar formation, which suggests that one giant impact led to the formation of the moon.

The new, multiple-impact hypothesis suggests that about 20 moon- to Mars-size objects struck the Earth, flinging debris from the planet into orbit. There, the debris formed disks around the Earth that looked somewhat like Saturn’s rings. Over centuries, debris in several disks accreted to form moonlets that migrated farther and farther from the Earth due to tidal interactions. Eventually, the moonlets settled at a distance known as the Hill radius, coalescing to form one big moon.

This process isn’t too far off from the “Giant Impact Hypothesis,” which states that a planet-size rock named Theia struck the Earth, leaving behind a jet of debris that went on to form the moon. But there’s one problem with this theory: it doesn’t provide a good explanation for the strong similarity between the composition of the moon and the Earth.

“The multiple-impact scenario is a more natural way of explaining the formation of the moon,” Raluca Rufu, a researcher at the Weizmann Institute of Science in Israel and lead author of the study, told Space.com. “In the early stages of the solar system, impacts were very abundant; therefore, it is more natural that several common impactors formed the moon, rather than one special one.

In a giant impact scenario, the object that struck the Earth would have needed an Earth-like composition to create a moon that is made of the same materials as Earth. If the impactor were composed of different stuff than Earth, the moon would not be so Earth-like in composition.

Authors of the new study, which was published today (Jan. 9) in the journal Nature Geoscience, performed several numerical simulations of moon-forming processes and determined that a multiple-impact scenario better explains the moon’s Earthly composition.

“Moreover, the composition similarity between the Earth and the moon in the giant impact cannot be explained without using a special Earth-like impactor,” Rufu added. “However, if multiple of bodies contribute to the final moon, their chemical signatures can even out, therefore the traces of the various impacts will be masked.”

Rufu also said that no existing evidence points more strongly to a single-impact hypothesis, though some studies have found that it is possible to reproduce the moon’s composition with a single impact if it strikes with enough angular momentum. Such an impact “will excavate more Earth material; hence the final moon composition is similar to Earth,” she said. “After the impact, the Earth-moon system has to lose the excess angular momentum.”

“To match both compositional and angular momentum constraints, the single giant-impact hypothesis requires such a specific type of collision that the moon’s formation becomes an uncomfortably improbable coincidence,” Gareth Collins, a planetary scientist at Imperial College London who studies impacts throughout the solar system, wrote in an accompanying Nature News & Views article. Collins wrote that the study revives “the hitherto largely discarded scenario that a series of smaller and more common impacts, rather than a single giant punch, formed the moon.”

Rufu and her colleagues are not the first to propose a multiple-impact scenario. Another paper published in 1989 raised that possibility, but “no further work was done on the subject,” Rufu said. “This paper is first to provide extensive calculations that we hope will stimulate others to reexamine the issue.”

Further research into the multiple-impact hypothesis is already underway. One of Rufu’s collaborators, physicist Hagai Perets of the Technion – Israel Institute of Technology, is already working to find out the efficiency of moonlet mergers. Rufu and her adviser also plan to study the moonlet-merging process “to understand the mixing of the moonlets inside the final moon.”

Special Notice: I Will Be On Coast to Coast AM Radio Tonight

I will be the guest tonight on Coast to Coast radio show with host Richard Syrett beginning at 11PM (PST) 1AM (CST) 2AM (EST). For your local AM station Click Here .

Here is a list of the topics we will most likely address:

-Signs of Coming Poll Shift – “We’re closer than you think.”

-There is a Big difference between the terms “Global Warming” and “Climate Change”

-What is the cause of ‘warming and cooling’ trends?

-Galactic Cosmic Rays and its effect on our Solar System, Sun, and Earth

-Why a full solar eclipse causes a spike in earthquakes, volcanoes, and various extreme weather events

-Likewise, why a full lunar eclipse can cause a spike in events – but for a different reason

-Fracking; a very bad idea.

I mentioned “likely” to address because it is “live” radio and you never know where a conversation will take us.    Cheers, Mitch

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Between now and January 15th 2017, by donating $10 you will be grandfathered into a full one year membership. Beginning January 1st 2017, we will be going back to our annual memberships starting at $34.95 per year. Yes, this is to say with just $10 you will have a full membership for the next full year of 2017.

For those of you who can do a bit more, we graciously appreciate when you can provide larger amounts – it truly goes a long way in keeping us alive and well.

Go to the following link which takes you to a page. On the right side of our home page under where it says “Science of Cycles Community Support” you will find a drop-down menu to choose your amount. Beginning next year we will have other methods for you to purchase a membership, for now please use PayPal. Remember, you do not have to join PayPal to use it. Just look for the tap that says Pay with Debit or Credit Card. No sign-up is necessary.……..CLICK HERE

Team of Researchers Catalog Tens of Thousands of Galaxies Beyond Our Milky Way

A team of researchers has compiled a special catalog to help astronomers figure out the true distances to tens of thousands of galaxies beyond our own Milky Way.

The catalog, called NED-D, is a critical resource, not only for studying these galaxies, but also for determining the distances to billions of other galaxies strewn throughout the universe. As the catalog continues to grow, astronomers can increasingly rely on it for ever-greater precision in calculating both how big the universe is and how fast it is expanding. NED-D is part of the NASA/IPAC Extragalactic Database (NED), an online repository containing information on more than 100 million galaxies.

“We’re thrilled to present this catalog of distances to galaxies as a valuable resource to the astronomical community,” said Ian Steer, NED team member, curator of NED-D, and lead author of a new report about the database appearing in The Astronomical Journal. “Learning a cosmic object’s distance is key to understanding its properties.”

Steer and colleagues presented the paper this week at the 229th meeting of the American Astronomical Society in Grapevine, Texas.

Since other galaxies are extremely far away, there’s no tape measure long enough to measure their distances from us. Instead, astronomers rely on extremely bright objects, such as Type La supernovae and pulsating stars called Cepheids variables, as indicators of distance. To calculate how far away a distant galaxy is, scientists use known mathematical relationships between distance and other properties of objects, such as their total emitted energy. More objects useful for these calculations have emerged in recent years. NED-D has revealed that there are now more than six dozen different indicators used to estimate such distances.

NED-D began as a small database pulled together in 2005 by Steer. He began serving at NED the following year to build out the database, poring over the scores of astronomical studies posted online daily, identifying newly calculated distance estimates as well as fresh analyses of older data.

From its humble origins a little over a decade ago, NED-D now hosts upwards of 166,000 distance estimates for more than 77,000 galaxies, along with estimates for some ultra-distant supernovae and energetic gamma ray bursts. To date, NED-D has been cited by researchers in hundreds of studies.

Besides providing a one-stop tabulation of the ever-increasing distance estimates published in the astronomical literature, NED-D—as well as the broader NED—can serve as “discovery engines.” By pooling tremendous amounts of searchable data, the information repositories can allow scientists to identify novel, exotic phenomena that otherwise would get lost in a deluge of observations. An example is the discovery of “super luminous” spiral galaxies by NED team members, reported last year, which were identified among nearly a million individual galaxies in the NED database.

“NED and its associated databases, including NED-D, are in the process of transforming from data look-up services to legitimate discovery engines for science,” said Steer. “Using NED today, astronomers can sift through mountains of ‘big data’ and discover additional new and amazing perspectives on our universe.”

The Elements of Life Mapped Across Milky Way

To say “we are stardust” may be a cliche, but it’s an undeniable fact that most of the essential elements of life are made in stars.

“For the first time, we can now study the distribution of elements across our Galaxy,” says Sten Hasselquist of New Mexico State University. “The elements we measure include the atoms that make up 97% of the mass of the human body.”

The new results come from a catalog of more than 150,000 stars; for each star, it includes the amount of each of almost two dozen chemical elements. The new catalog includes all of the so-called “CHNOPS elements” – carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur – known to be the building blocks of all life on Earth.

This is the first time that measurements of all of the CHNOPS elements have been made for such a large number of stars.

How do we know how much of each element a star contains? Of course, astronomers cannot visit stars to spoon up a sample of what they’re made of, so they instead use a technique called spectroscopy to make these measurements. This technique splits light – in this case, light from distant stars – into detailed rainbows (called spectra). We can work out how much of each element a star contains by measuring the depths of the dark and bright patches in the spectra caused by different elements.

Astronomers in the Sloan Digital Sky Survey have made these observations using the APOGEE (Apache Point Observatory Galactic Evolution Experiment) spectrograph on the 2.5m Sloan Foundation Telescope at Apache Point Observatory in New Mexico. This instrument collects light in the near-infrared part of the electromagnetic spectrum and disperses it, like a prism, to reveal signatures of different elements in the atmospheres of stars. A fraction of the almost 200,000 stars surveyed by APOGEE overlap with the sample of stars targeted by the NASA Kepler mission, which was designed to find potentially Earth-like planets. The work presented today focuses on ninety Kepler stars that show evidence of hosting rocky planets, and which have also been surveyed by APOGEE.

While the Sloan Digital Sky Survey may be best known for its beautiful public images of the sky, since 2008 it has been entirely a spectroscopic survey. The current stellar chemistry measurements use a spectrograph that senses infrared light – the APOGEE (Apache Point Observatory Galactic Evolution Experiment) spectrograph, mounted on the 2.5-meter Sloan Foundation Telescope at Apache Point Observatory in New Mexico.

Jon Holtzman of New Mexico State University explains that “by working in the infrared part of the spectrum, APOGEE can see stars across much more of the Milky Way than if it were trying to observe in visible light. Infrared light passes through the interstellar dust, and APOGEE helps us observe a broad range of wavelengths in detail, so we can measure the patterns created by dozens of different elements.”

The new catalog is already helping astronomers gain a new understanding of the history and structure of our Galaxy, but the catalog also demonstrates a clear human connection to the skies. As the famous astronomer Carl Sagan said, “we are made of starstuff.” Many of the atoms which make up your body were created sometime in the distant past inside of stars, and those atoms have made long journeys from those ancient stars to you.

While humans are 65% oxygen by mass, oxygen makes up less than 1% of the mass of all of elements in space. Stars are mostly hydrogen, but small amounts of heavier elements such as oxygen can be detected in the spectra of stars. With these new results, APOGEE has found more of these heavier elements in the inner Galaxy. Stars in the inner galaxy are also older, so this means more of the elements of life were synthesized earlier in the inner parts of the Galaxy than in the outer parts.

While it’s fun speculate what impact the inner Galaxy’s composition might have on where life pops up, we are much better at understanding the formation of stars in our Galaxy. Because the processes producing each element occur in specific types of stars and proceed at different rates, they leave specific signatures in the chemical abundance patterns measured by SDSS/APOGEE. This means that SDSS/APOGEE’s new elemental abundance catalog provides data to compare with the predictions made by models of galaxy formation.

Jon Bird of Vanderbilt University, who works on modelling the Milky Way, explains that “these data will be useful to make progress on understanding Galactic evolution, as more and more detailed simulations of the formation of our galaxy are being made, requiring more complex data for comparison.”

“It’s a great human interest story that we are now able to map the abundance of all of the major elements found in the human body across hundreds of thousands of stars in our Milky Way,” said Jennifer Johnson of The Ohio State University. “This allows us to place constraints on when and where in our galaxy life had the required elements to evolve, a sort ‘temporal Galactic habitable zone'”.